The present invention relates to the use of a lubricant interface in a data storage drive and relates more specifically to the reduction of a temperature in the lubricant interface.
In prior art data storage systems that incorporate flying head technology, a thin lubricating layer is deposited on a surface of a rotating disk such that surface tribology and aerodynamics are adequate to maintain the head in a flying condition over the disk. In the prior art, however, lubricant contamination of the head from the lubricant layer has been observed and can be largely attributed to heating of the lubricant layer. Thermal modeling of the prior art shows that the lubricant layer may reach temperatures of several hundred degrees Celsius when heated, such as during a laser optical reading/writing process. Additionally, kinetic theory shows that evaporated lubricant molecules have enough speed to reach and condense on transducer regions of the head before the head has an opportunity to translate away from the portion of the lubricating layer that is heated by the laser light. In a head embodiment that comprises apertures, there may also be a tendency for the evaporated lubricant to condense in the apertures. In head embodiments that utilize optical and/or electrical components in these apertures, the evaporated lubricant layer may condense on the components to degrade their performance. In the prior art the evaporated lubricant may act to degrade the performance of the head such that acceptable long-term head performance becomes impossible in the data storage system.
What is needed, therefore, is an improvement over the prior art that minimizes or eliminates the limitations of the prior art.
The present invention comprises a thick dielectric insulating layer combined with a heat conducting layer at an air/disk interface to provide a potentially simple solution to the problem of interference with optical head performance via lubricant heating. A liquid lubricant head/disk interface as part of the optical path may also be used. The insulating material should be optically transparent and possess a high heat capacity. In one embodiment, the insulating layer is used to generate a large temperature gradient between the MO layer and the disk surface to reduce the surface temperature and lubricant evaporation.
The present invention includes a data storage system, comprising a source of heat, a substrate, a storage layer disposed above the substrate, a lubricant layer disposed above the storage layer, the lubricant layer comprising molecules, a flying head disposed above the lubricant layer, and a dielectric layer disposed between the lubricant layer and the storage layer, wherein the dielectric layer comprises a heat capacity that is sufficient to reduce release of the molecules from the lubricant layer when the storage layer is heated by the source of heat such that contamination of the flying head by the molecules is substantially reduced. The flying head may comprise a far field optical head. The flying head may comprise a near field optical head. The dielectric layer may comprise a thickness of at least 200 nm. The dielectric layer may comprise SiN. The present invention may further comprise a liquid lubricant, wherein the liquid lubricant is disposed between the near field optical flying head and the lubricant layer. The liquid lubricant layer may comprise a branch chained hydrocarbon such as C16, a flourinated solvent such as PFPE, or other similar optically transparent materials. The dielectric layer may comprise a thickness of at least 200 nm.
The present invention also includes a data storage disk, comprising: a substrate, a storage layer disposed above the substrate, a lubricant layer disposed above the substrate, the lubricant layer comprising molecules, and a dielectric layer disposed between the lubricant layer and the storage layer, wherein the dielectric layer comprises a heat capacity that is sufficient to substantially reduce release of the molecules from the lubricant layer when the storage layer is heated.
The present invention also includes a data storage system, comprising: storage means for storing data, lubricant means for providing a lubricant interface to the storage means, heating means for applying heat, and heat dissipation means for reducing a temperature increase of the lubricant means caused by the heating means to a level whereby the lubricating means does not interfere with optical operation of the data storage system. The storage means may comprise a flying optical head. The heat dissipation means may comprise a dielectric layer disposed between the storage means and the lubricant means. The dielectric layer may comprise a thickness of at least 200 nm. The storage means may comprise an MO layer. The heat dissipation means may comprise the lubricant means. The lubricant means may comprise a liquid lubricant. The flying optical head may comprise a near field flying optical head. The heat dissipation means may comprise a dielectric layer.